A vehicle comes in with the MIL (Malfunction Indicator Light) on, showing DTC (Diagnostic Trouble Code) P0456, indicating a small leak detected in the EVAP canister system.

Technician A says a defective vent solenoid or a leak could be the cause.
Technician B says a wrong or defective gas cap could be the cause.

Who is right?

a. A only
b. B only
c. Both A and B
d. Neither A nor B

Technician A and Technician B are both correct. A defective vent solenoid, a leak, or a wrong/defective gas cap could be the cause of the small leak detected in the EVAP canister system (DTC P0456).

Explanation:

Technician A and Technician B are both correct. DTC P0456 indicates a small leak detected in the EVAP (Evaporative Emission) canister system. This system helps prevent harmful fuel vapors from escaping into the atmosphere. A defective vent solenoid or a leak in the system can be the cause of the code. Technician A is correct in identifying these possible causes.

In addition, Technician B is also correct. A wrong or defective gas cap can cause a small leak in the EVAP canister system. The gas cap is an important component of the system and it helps maintain proper pressure. If the gas cap is not sealing correctly or is damaged, it can lead to a small leak and trigger the MIL with the DTC P0456.

Therefore, the correct answer is Both A and B.